The present invention relates to a sheet material accumulating device and particularly to a sheet material accumulating device in which sheet materials which are likely to be damaged, are accumulated in such a manner that rubbing contact between sheets is substantially eliminated.
There has been proposed an apparatus by which a radiation image of the human body or the like is recorded onto a stumulable phosphor plate and the image information recorded thereon is read out by means of a laser scanner or the like and then a visible image is reproduced by exposing a recording medium, such as a photosensitive film or the like to a modulated light beam carrying the image information recorded the stumulable phosphor plate. In such a picture image forming apparatus, the stimulable phosphor plate for image storage is generally in sheet form. After these phosphor sheets have been exposed to radiation images, they are fed into a sheet supply section of a radiant image reading machine. This feeding operation may be accomplished manually or with the use of a transport system such as a conveyer. The phospor sheets are then automatically fed, one by one, into a reading section from the sheet supply section. In many cases, and particularly in the case of a medical care/diagnostic apparatus, the photographing of radiation images is performed aperiodically. Therefore, even in the case where a radiation lay image photgraphing device and a radiation picture image reading device are coupled to each other through a sheet transport system, it is preferable to arrange the entire device such that the photographing device and the image reading device are not directly coupled. Rather, it is preferable to store the phospor sheets at a sheet receiving position before they are transported to the image reading device. Generally, the stored phosphor sheets are transported in groups, from the sheet receiving position into a sheet transfer position. From there the phosphor sheets are fed, one by one, to the image reading section from the transfer position. If the sheet feed is performed in this manner, it is possible to cause the radiation image reading device to operate with its running cycle completely independent of the timing of the phosphor sheet feeding mechanism of the radiation image photographing device. Further, if such a sheet feed system as mentioned above is employed, even in the case where a fault occurs in the radiation image reading device or in the case where the radiation image photographing device temporarily feeds a number of phosphor sheets beyond the processing capacity of the radiation image reading device, it is not necessary to immediately stop the radiation image photographing device, for it is possible for the image photographing device to continue operating an additional period of time.
When sheet materials are accumulated at a sheet receiving position, thesheet receiving device has been conventionally operated to receive aperiodically fed sheet materials and accumulate them in such a manner that they are caused to successively stand along a slanted guide plate.
In the conventional accumulating device of this type, however, there is the problem that since newly fed sheet material is fed onto sheet materials which have previously been accumulated, that is, the already accumulated sheet materials serve as a guide plate for a newly fed sheet, the sheet materials may be damaged, especially if the sheet materials are likely to be damaged as are the above-mentioned phosphor sheets. This problem is more significant in the case where a sheet material is curled.
Further, when using the conventional sheet accumulating device, in the case where various sheet materials of different sizes are to be accumulated, there often occurs the problem that with sheet material which is shorter in its longitudinal direction, the sheet material may hit a sheet receiver with a shock larger than that produced by a longer sheet, with the result that it may be damaged or improperly stacked on the sheet receiver thereby causing an irregularly stacked accumulation of sheet materials.